Measuring moisture content

Moisture content (MC) is the weight of water contained in paddy or rice expressed in percent. MC is usually referred to the wet basis meaning the total weight of the grain including the water (MCwb). For research moisture content referred to the dry matter of the grain is sometimes used (MCdb).

Why is measuring the moisture content important?


Accurate moisture content testing is important in managing and marketing paddy and rice because depending on the purpose rice has different ideal moisture contents. Inaccurate moisture content measurements lead to:

  • Extra drying cost and harvesting loss if paddy is harvested wetter than necessary
  • Spoilage if the grain is too wet in storage
  • Extra drying cost and loss of quality if paddy is dried too far
  • Lower head rice when milled at wrong MC
  • Weight loss (loss in profit) if grain is sold too dry

How to measure moisture content

Moisture content of grain can be measured by using either:

  • primary method, based on weight measurements like the (a) oven method or an (b) infrared moisture balance or
  • secondary method, using an electronic instrument that uses electrical characteristics of the grains.

Many different types of portable grain moisture meters can be used to measure the moisture content. When selecting a meter, make sure it is suitable for harvesting paddy or milling grain, depending on which activity you are doing. 

Read: Types of portable moisture meters

in Harvesting

Higher moisture content results in more losses from poor grain quality; while, lower moisture content results in more losses from shattering.

For measuring moisture content during harvesting, the most practical option is to use a resistance-type moisture meter that gives quick results and only uses small samples.

The capacitive moisture meters are more expensive, require a larger sample, but are more accurate than resistance type units.

The following table summarizes the target moisture content for each of the key postproduction operation:


Desired moisture content

Primary losses


  • 20–25%
  • shattering if grain is too dry
  • unfilled and many green grains if too wet


  • 20–25% for mechanical threshing
  • less than 20% for hand threshing
  • incomplete threshing, grain damage, and cracking/breakage


  • final moisture content is 14% or lower
  • spoilage, fungal damage, discoloration


  • less than 14% for grain storage
  • than 12% for seed storage 
  • less than 9% for long term seed preservation
  • fungal, insect, and rat damage 
  • loss of vigor 
  • loss of vigor


  • 13–14%
  • grain cracking and breakage